Method of recording and reproducing sound



TES-

tems unrssnsn or anemia, GERMANY, ASSIGNOR 'ro ensnnnscm'rr run ions'n'rnosn' rnnnemnm Min. rona'rron' or GERMANY.

n. nannnsonns; or nnnn MANY; C03,

5 Marion or nnconnrne Ann nnrnonncmo sonivn. 1

. No Drawing. Application iiled November 11, 1922, Serial li o, 600,429, and in Germany November 11, 1 921.

In the use of the met-hodheretofdre em ployed for recording and reproducing so'u'nd,the same arrangement mustbe used for reproducing the whole "sound intensity as well as the sound rhythm. The recording must, therefore, be eflected at a very greatintensity so that, during the reproduction, the. stylus may .perform the; whole sound work. The stylus vmust undergo large I movements to follow the deep grooves of the ,-record, and the stylus encounters very reat "frictional resistances. These frictiona rehardening ofthe record causes the frictional sistances' and the strong movements of the stylus cause in tufii strong side-tones resultingfrom theengagement of the stylus with the record, which may be in the form of a disc, roll, etc.' The pressure of the stylus on the disc or otherrecord results in a further technical .difliculty in that the record must be hardened by meanslof the admixture of resinous substances and the like. Such and side-tones to be further increased. These noises due to. friction between the stylus and the. record constitute the main short-comingofnthe present day acoustical apparatus. Their cause is not solely in the disc or other record but also in the sound box.

In'accordance with the present invention,

such noises are materially reduced by separating the functions of the stylus in such a manner that its acoustical work is materially lessened. To; this end, when .the 'record is made, the stylus is caused to make only slight movements, such movements being so small that the resultant grooves are insufiicient for audibly reproducingthe sound intensity. The function of the grooves is only to reproduce the form of the acoustical curve and notfto produce the full intensity .of the. During reproduction, the shallow oves offer less frictional resistance to t e stylus and the stylus. performsa much slightermovement. -The reproducing sound box system may also be materially simplified. Furthermore it is no longer necessary to add hardening substances to the -materialcomposing" the record disk. Electrical amplify-ing arrangements are provided for producing sound of the desired intensity.

The sound work of thestylus acts on a mi-' crophone arrangeipenk-e. g. a microphone microphone currents being amplified in the usual manner and transmitted at any desired provided on the reproducer diaphragm, the

strength to the hornof the soundreproduc- 1 to any apparatus which makes use of record ing and reproducing by means of a stylus on a blank record. 7

Having described my invention, what I claim is:

1. A ,method of recording and reproducing sound which consists .in producing one record a shallow groove having the form of an acoustlcal curve, reproducingthe sound at low amplitude requiring less energy than is necessary to produce audible sounds by means of a stylus, and electrically amplifymg the sound to bring it up to normal'intensity.

2. A method of recording and reproducing sound, which consists in forming an acoustical curve on a record by means of a stylus, causing the record during the recording to be only slightly affected by the stylus so that the acoustical curve, formed on the record is insuflicient for the reproduction of audible sound, reproducing the sound at low amplitude by means of a stylus, and electrically amplifying the sound to bring it up to normal intensity.

3. A method of recording and reproducing sound which consists in operating on a record with a stylus to produce a groove having the form of an acoustical curve and being too shallow to enable direct reproduction of the sound at audible intensity, me-

chanicallyreproducing the sound at low amplitude and electrically amplifying the sound.

4. A method V lus a sound groove by imparting just to record the acoustical curve, and then reproducin said sound by taking an inaudible degree 0 energy from said record and suitof recording and reproduc-. 1 ng sound which consists in recording on ablank "record by means of a cient energy ably amplifying said energy by a suitable suflicient amplitude to accurately record an 10 amplifier. inaudible form of the sound Wave.

5. A method of recording sound which 7, A method of recording sound which 4 consists in recording on a blank record by consists in recording on a blank record by meansrof a stylus sound undulations of an means of a stylus mechanism sound unduinaudible degree of amplitude. lations of such amplitude as to be inaudible 15 6. A method of recording sound which if reproduced directly by means of said consists in recording on a blank record by stylus mechanism. means of a stylus sound undulations of just DR. ALEXANDER MEISSNER. 

